There were already variable speed zones outside Horowhenua College, St Joseph's School, Koputaroa School and Opiki School.
HDC received 98 written submissions within weeks, and an online survey of 740 people showed a strong majority in favour of lowering speed limits.
The review followed changes in legislation that required speed limits to be reviewed and set in line with an updated NZTA requirements.
Council Roading Services manager Kevin Peel said every effort would be made to ensure the changes were consistent to avoid confusion.
"The new limits ensure speed zones accurately reflect safety risk to road users. The new speed zones will also be more consistent and minimise frequent speed limit changes to avoid driver confusion," he said.
"In the past council received multiple requests from the public to look at implementing lower speed limits on some rural roads, in particular in areas where there had been significant rural residential development or growth in commercial activities."
Old legislation set speed limits with a default limit of 100km/h, a rate no longer suitable to a changing roading environment, he said.
Several members of the public spoke to their submissions, including Hokio Beach Rd resident Malcolm Hadlum, who suggested there were parts of his road that need a limit lower than 80km/h to ensure safety.
Councillor Barry Judd agreed and said it was not unusual to see a car upside down in a paddock along Hokio Beach Rd.
Peel said the new limits would require tweaking in some areas, which would take time. The new limits would be formally ratified in mid-August following a public notification period.
Meanwhile, a new 50km/h limit has found favour with members of the Levin Racing Club who have long feared speeding drivers along Mako Mako Rd were putting lives at risk.
Hundreds of horses and their riders cross the road each week, often at early hours of the morning, and some motorists have been using the road as a racing strip along a 70km/h stretch.
Levin Track Trust manager Bruce McCarrison said there were multiple near misses over the years as drivers reached ridiculous speeds, posing a danger not only to horse and rider, but the motorist themselves.
"The average horse weighs 500kg and if a car hits ... there's been some narrow escapes, I can tell you," he said.
"If you know there is a potential risk then you have an obligation to prevent that risk. It's been an accident waiting to happen. This is a move in the right direction."
Levin Racing Club president Ian Gray said he applauded the new limits as a step in the right direction.
"I hope it is policed to make people abide by the rules," he said.
